The present invention relates to an improved apparatus and method for generating an additional sound on the basis of a sound signal representative of a human voice or musical tone, and a storage medium containing a processing program for generating such an additional sound.
There has been known, from Japanese Patent Laid-open Publication No. HEI-11-133990 or the like, a technique for detecting, in real time, a pitch of a vocal signal input by a user (i.e., a user-input vocal signal), modifying the detected pitch of the input vocal signal to generate a harmony sound signal in accordance with a predetermined harmony mode, and then combining the harmony sound signal with the original input vocal signal to thereby output the combined result through speakers. Examples of the predetermined harmony mode used for such a purpose include a xe2x80x9cvocoder harmony modexe2x80x9d, xe2x80x9cchordal harmony modexe2x80x9d, xe2x80x9cdetune harmony modexe2x80x9d and xe2x80x9cchromatic harmony modexe2x80x9d.
FIG. 11 is a diagram explanatory of various types of harmonies attainable when the conventionally-known technique operates in the vocoder harmony mode. The vocoder harmony mode is a mode in which playing a key in a specific key region of a keyboard performance operator section, selected as a harmony part, simultaneously with input of a human voice can generate a harmony sound (i.e., harmony note) with a vocal character of the input voice and with a pitch corresponding to a scale note pitch of the played key on the keyboard performance operator section. The harmony part that can be designated here is not necessarily limited to the right-hand (UPPER) key region or left-hand (LOWER) key region of the keyboard performance operator section, and can also be selected by a user from among an automatic performance song track, external input or the like. Depending on the harmony type designated, the harmony sound to be generated is octave-shifted from the scale note pitch of the harmony part, or shifted from the scale note pitch of the harmony part to within one octave about the pitch of the input voice (auto transpose), or the like.
FIG. 12 is a diagram explanatory of a type of harmony attainable when the conventionally-known technique operates in the detune harmony mode, which is a mode intended to impart a chorus effect by generating a harmony sound slightly shifted in pitch from an input voice. Scale note pitch of the harmony sound is governed by the input voice and amount of the detune. Although only one type of harmony is shown in the figure, a plurality types of harmonies can be set in the detune harmony mode by changing the detune amount.
FIG. 13 a diagram explanatory of types of harmonies attainable when the conventionally-known technique operates in the chromatic harmony mode, which is a mode intended to generate a harmony sound shifted in pitch from an input voice by a predetermined interval. In this case too, the scale note pitch of the harmony sound is governed by the input voice and amount of the pitch shift. The pitch shift amount is varied in accordance with a switch between the harmony types.
Further, FIG. 14 a diagram explanatory of types of harmonies attainable when the conventionally-known technique operates in the chordal harmony mode. The chordal harmony mode is a mode in which a type of a chord designated by a key in an automatic accompaniment chord key region of the keyboard performance operator section is identified and then one or more harmony sounds are generated in accordance with the identified chord type and with pitches corresponding to a pitch of an input voice. In this mode, only inputting the voice can generate harmony sounds corresponding to the designated chord type. In the chordal harmony mode, 37 different chord types as defined in the MIDI specifications are identifiable, and the pitches of the harmony sounds are determined in accordance with the harmony type, identified chord type and a scale note pitch (vocal note) nearest to the pitch of the input voice.
Throughout this patent specification, the terms xe2x80x9cscale note pitchxe2x80x9d are used to refer to a pitch corresponding to one of note names on a chromatic scale (12 notes per octave), and it is assumed that pitch frequencies are predefined in half steps or semitones. The note names are also called xe2x80x9cnote codesxe2x80x9d in the MIDI specifications and allotted unique numbers xe2x80x9c0xe2x80x9d-xe2x80x9c127xe2x80x9d (with note name xe2x80x9cC4xe2x80x9d allotted number xe2x80x9c60xe2x80x9d). However, in some cases, the pitch frequencies corresponding to the note names are associated with frequencies shifted from the absolute frequencies where note name xe2x80x9cA4xe2x80x9d is 440 Hz, or the pure temperament (just intonation) system is employed rather than the temperament system.
In the chordal harmony mode, there can be produced a variety of harmony sounds by switching between the harmony types. Selection can be made between xe2x80x9cone voicexe2x80x9d and xe2x80x9ctwo voicexe2x80x9d, and harmony sounds of different scale note pitches, one above the input voice pitch and the other below the input voice pitch, can be designated. Also, xe2x80x9cone voice bassxe2x80x9d represents a harmony sound having, as its scale note pitch, a root note of a designated chord. In xe2x80x9cunisonxe2x80x9d, selection is made from among harmony sounds of a scale note pitch agreeing with the pitch of the input voice and pitches higher and lower than the input voice pitch by one or more octaves.
In the above-mentioned detune harmony mode or chromatic harmony mode, the harmony sound is set to a scale note pitch detuned or shifted from the pitch of the input vocal signal (vocal pitch). Thus, by detuning or pitch-shifting from the vocal pitch itself, there can always be maintained a proportional relationship in pitch frequency between the input voice and the harmony sound. In the above-mentioned vocoder harmony mode and chordal harmony mode, on the other hand, each harmony sound is set to a scale note pitch corresponding to a pitch designated by operation of a keyboard key or by designation of a chord. The scale note pitch is predefined in half steps. Namely, in the vocoder harmony mode, the harmony sound is imparted with a pitch corresponding to a scale note pitch of the harmony part, or a pitch transposed by octave from the scale note pitch of the harmony part pitch. Further, in the chordal harmony mode, scale note pitches are designated for the harmony sounds in accordance with the scale note pitch nearest to the pitch of the input voice and designated chord, and then the harmony sounds are imparted with pitches corresponding to the designated scale note pitches and predefined in half steps.
According to a first aspect of the present invention, there is provided an apparatus for generating an additional sound signal on the basis of an input sound signal, which comprises: an input device adapted to receive control information for controlling a pitch of an additional sound; and a processor device coupled with the input device. The processor device is adapted to: obtain pitch information of the input sound signal; obtain, on the basis of at least the control information received via the input device, scale note pitch information of an additional sound to be generated; determine a scale note pitch nearest to a pitch indicated by the pitch information of the input sound signal; modify, in accordance with a difference between the determined scale note pitch and the pitch of the input sound signal, a pitch indicated by the scale note pitch information of the additional sound to be generated; and generate an additional sound signal with the modified pitch.
According to a second aspect of the present invention, there is provided an apparatus for generating an additional sound signal on the basis of an input sound signal, which comprises: a data supply section adapted to supply scale note pitch data varying over time; an input device adapted to receive control information for controlling a pitch of an additional sound; and a processor device coupled with the data supply section and the input device, the processor device being adapted to: obtain pitch information of the input sound signal; obtain, on the basis of at least the control information received via the input device, scale note pitch information of an additional sound to be generated; modify, in accordance with a difference between a pitch indicated by the pitch information of the input sound signal and a pitch indicated by the scale note pitch data supplied by the data supply section, a pitch indicated by the scale note pitch information of the additional sound to be generated; and generate an additional sound signal with the modified pitch.
The present invention may be constructed and implemented not only as the apparatus invention as discussed above but also as a method invention. Also, the present invention may be arranged and implemented as a software program for execution by a processor such as a computer or DSP, as well as a storage medium storing such a program. Further, the processor used in the present invention may comprise a dedicated processor with dedicated logic built in hardware, rather than a computer or other general-purpose type processor capable of running a desired software program.
While the embodiments to be described herein represent the preferred form of the present invention, it is to be understood that various modifications will occur to those skilled in the art without departing from the spirit of the invention. The scope of the present invention is therefore to be determined solely by the appended claims.